如何在UIScrollView中实现夹点以关闭功能？

Question

当用户通过捏出图片将图像放大到足够远时，我希望它关闭UIImageView/滚动视图，基本上退出图片查看器。

我该怎么做呢？scrollViewDidEndZooming是在动画化后被调用的，所以我不能使用它，其他的委托方法似乎都没有帮助。

Answer 1

我已经为我的一个应用程序创建了这个效果，别忘了设置滚动视图的委托。您需要用捏手势更新私有方法(仅此而已)。

.h文件代码

#import <UIKit/UIKit.h>

@interface ImageViewerController : UIViewController<UIScrollViewDelegate>

// The scroll view used for zooming.
@property (weak, nonatomic) IBOutlet UIScrollView *scrollView;

// The image view that displays the image.
@property (weak, nonatomic) IBOutlet UIImageView *imageView;

// The image that will be shown.
@property (strong, nonatomic) NSString *imageUrlString;

@end

.m代码

#import "ImageViewerController.h"

@interface HNImageViewerController ()

- (IBAction)handleSingleTap:(UIButton*)tapGestureRecognizer;
@end

@implementation ImageViewerController

- (void)viewDidLoad {
[super viewDidLoad];
[self.imageView setImage:[UIImage imageNamed:@"placeholder-image"]];
self.scrollView.delegate=self;
}

- (BOOL)prefersStatusBarHidden {
return YES;
}

#pragma mark - UIScrollViewDelegate methods

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return self.imageView;
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
if (self.scrollView.zoomScale == self.scrollView.minimumZoomScale) {
    [self dismissViewControllerAnimated:YES completion:nil];
}
}

#pragma mark - Private methods

- (IBAction)handleSingleTap:(UIButton *)tapGestureRecognizer {

[self dismissViewControllerAnimated:YES completion:nil];
}